Understanding the role of human genes in normal development and in disease will be accomplished primarily in the mouse which has a remarkable 99% gene overlap with the human. Finding and identifying human diseases is crucially dependent on medical imaging. Finding and monitoring comparable diseases in mice will be just as crucially dependent on mouse imaging. It is, therefore, important to adapt the range of human imaging modalities to the scale of the mouse where possible. This application proposes to adapt magnetic resonance imaging (MRI) to the mouse and to solve the through put bottleneck by imaging multiple mice (MMMRI) in parallel in the same magnet. This will increase throughput 19 fold. Implementation of MMMRI requires solving issues of RF coil interference, simultaneous data acquisition, large data reconstruction, handling, anesthesia and monitoring of multiple mice, and motion correction methods. After the MMMRI has been developed and tested, its use will be demonstrated in primary screening of NU mutagenized mice, characterizing normal ranges of anatomical variations in inbred strains of mice, detailed mapping of the structures of excised organs (brain and heart), and following the time course of cancer progression in mouse models of brain tumors.